Definition
The GCLID (Google Click Identifier) is a parameter that Google Ads adds to landing page URLs when auto-tagging is on, so conversions can be tied back to the click.
In practice
GA4 and the Google tag read the GCLID and store it in a first-party cookie, which is how website conversions are linked to campaigns, ad groups and keywords.
Saving the GCLID with a lead in your CRM makes offline conversion imports possible, so a sale weeks later can still be credited to the original click. On iOS traffic, Google may use the gbraid or wbraid parameters instead.
Redirects that strip query parameters, or forms that do not carry the value through, are the usual reasons GCLIDs go missing.
Learn more: Google Ads AI Agent.
Related terms
- UTM parametersUTM parameters are tags added to a link, such as utm_source, utm_medium and utm_campaign, that tell analytics tools where a visit came from.
- Enhanced conversionsEnhanced conversions is a Google Ads feature that sends hashed first-party customer data, such as email or phone, along with a conversion so Google can match it to signed-in users.
- Data-driven attributionData-driven attribution is a model that splits credit for a conversion across the ads and channels a person interacted with, based on how much each touchpoint actually contributed.
How Markitech helps
Markitech connects your AI to Google Ads, GA4, Google Tag Manager, Meta and 12 more platforms, so it can check how GCLID is set up in your own accounts and tags and propose fixes. Every change is held until you approve it.